Revert "[PA/AC] UI thread specific capacity configuration for quarantine"

This reverts commit e92ef522a4d574e9da58f07b2fa1f2d34a8b18b2.

Reason for revert: many testers failing with CHECK added with the CL.
Although the code is located behind the flag, I assume the flag is
enabled on CI/CQ due to the field trial testing config.
See crbug.com/388378769

Original change's description:
> [PA/AC] UI thread specific capacity configuration for quarantine
>
> As we are planning to start an experiment over PartitionAlloc with
> Advanced Checks (PA/AC) in the browser UI thread only, it should be
> capable of thread-type-aware capacity configuration.
> This CL will add single FeatureParam which is UI-thread specific
> quarantine capacity value.
>
> Bug: 351974425, 387470567
> Change-Id: I66bb24d051bdbf684ae5848351bd8c0bb1903539
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6151471
> Reviewed-by: Takashi Sakamoto <tasak@google.com>
> Commit-Queue: Mikihito Matsuura <mikt@google.com>
> Cr-Commit-Position: refs/heads/main@{#1403352}

Bug: 351974425, 387470567
Bug: 388378769
Change-Id: Ieeecc2f19425281af7cf26b99686f76d65573320
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6156535
Auto-Submit: Yoshisato Yanagisawa <yyanagisawa@google.com>
Owners-Override: Yoshisato Yanagisawa <yyanagisawa@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1403400}
NOKEYCHECK=True
GitOrigin-RevId: 5388c07259222fb1110f5d51362b43640051fcaa
diff --git a/src/partition_alloc/partition_root.h b/src/partition_alloc/partition_root.h
index 7667c45..b65c017 100644
--- a/src/partition_alloc/partition_root.h
+++ b/src/partition_alloc/partition_root.h
@@ -893,14 +893,6 @@
     return GetSchedulerLoopQuarantineBranch();
   }
 
-  void SetSchedulerLoopQuarantineThreadLocalBranchCapacity(
-      size_t capacity_in_bytes) {
-    ThreadCache* thread_cache = this->GetOrCreateThreadCache();
-    PA_CHECK(ThreadCache::IsValid(thread_cache));
-    thread_cache->GetSchedulerLoopQuarantineBranch().SetCapacityInBytes(
-        capacity_in_bytes);
-  }
-
   const internal::PartitionFreelistDispatcher* get_freelist_dispatcher() {
 #if PA_BUILDFLAG(USE_FREELIST_DISPATCHER)
     if (settings.use_pool_offset_freelists) {